This study was designed to determine the threshold dose for toxicity, the potential for serious medical complications, and the medical care required after unintentional albuterol ingestion in children. This study was prospective and descriptive. Data were obtained on pediatric albuterol ingestions evaluated emergently as reported to three regional poison control centers. Data elements included dose ingested, physical findings, medical treatment, and outcome. During 18 months, 78 patients who ingested albuterol and who received urgent medical evaluation were identified. Mean age was 2.8 years. The amount ingested ranged from 0.2 to 8.8 mg/kg. The most commonly reported signs of toxicity were tachycardia (57%, 44/78), widened pulse pressure (50%, 27/54), hyperglycemia (50%, 12/24), agitation (45%, 35/78), low serum carbon dioxide (42%, 10/24), vomiting (26%, 20/78), and hypokalemia (26%, 9/35). We found a threshold dose o 1 mg/kg for three or more signs of toxicity (P < 0.01). No patient required any specific treatment for toxicity. Seventy-two percent of patients were discharged from medical care within six hours of ingestion. Albuterol overdose in children causes a variety of cardiovascular, neuromuscular, and metabolic effects that are usually benign. The threshold dose for the development of three or more signs of toxicity is 1 mg/kg or three to 10 times the recommended daily dose. Toxicity is short-lived and does not require specific therapy or hospital admission in most cases.